Unused Underground Home Heating Oil Tank Q&A

Like many things buried below the ground, underground home heating oil tanks can remain mysterious to the average person. In this piece, we’re going to do our best to quickly answer some questions asked about these subterranean tanks and their possible environmental implications.

How do I know if there is an underground home heating oil tank on my property?

While it may be difficult to detect the underground presence of a home heating oil tank itself, there are a few telltale signs. The main sign to look for is a fill cap as well as a vent pipe sticking up out of the ground. Fill caps are frequently flush with the ground, making spotting them a challenging feat in some instances. The use of a rented metal detector may be necessary in order to locate a tank fill cap. Another sign that a tank may be located on your property is piping leading to your house whose purpose is unclear.

What should I do once an unused underground home heating oil tank is located?

In order to ensure that no further environmental consequences are possible from a located tank, it is recommended that all unused underground home heating oil tanks are removed. Another option is to “abandon” the tank in place, but additional steps will be required to limit potential ecological damage from leaking or failure of the tank’s structural integrity. If the tank is abandoned in place, it should be completely emptied of any hazardous material and filled with some form of inert material such as sand or cement. Filling the tank with an inert material will prevent tank collapse which may later lead to sinkholes. Empty tanks also run the risk of floating to the surface if the soil above it is loosened during flooding. While on-site abandoning is an option, the recommended treatment of unused buried tanks is complete tank removal. This is the only way to truly ensure no additional environmental consequences take place.

How do I know if an underground tank is leaking?

A few signs that a buried tank is leaking fuel will be either dead vegetation surrounding the fill pipe of a tank or a strong petroleum smell from the fill cap or area around the tank itself. The soil surrounding the tank may also have a green-gray hue. If you’re still unsure whether or not an underground tank is leaking, tests of the surrounding soil can determine the presence of fuel.

Why do underground tanks leak fuel?

The biggest culprit of leaking in underground tanks is the corrosion of the tank itself. Fuel may also find its way out of a tank through the fill cap or vent due to water leaking into the tank. The oil is will float on top of the water in the tank. As the amount of water in the tank increases, it will force the oil up and out of the fill cap and/or vent mechanism.